This still image from a new simulation shows how plasma from the pedestal region is connected through the supposedly last confinement surface into the divertor plasma region. The long and thin lobes are fluctuating in time and space. (Simulation credit: Seung-Hoe Ku / Princeton Plasma Physics Laboratory on the Department of Energy's Summit computer at Oak Ridge National Laboratory; Visualization credit: Dave Pugmire and Jong Youl Choi / Oak Ridge National Laboratory).
The intense heat generated by a fusing plasma in a commercial-scale reactor may not be as damaging to the vessel’s innards as once thought, according to researchers at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL), Oak Ridge National Laboratory and the ITER organization (ITER).
“This discovery fundamentally changes how we think about the way heat and particles travel between two critically important regions at the edge of a plasma during fusion,” said PPPL Managing Principal Research Physicist Choongseok Chang, who led the team of researchers behind the discovery. A new paper detailing their work was recently published in the journal Nuclear Fusion, following previous publications on the subject.
Past research based on physics and experimental data from present-day tokamaks suggested exhaust heat would focus on a very narrow band along a part of the tokamak wall known as the divertor plates. Dedicated to removing exhaust heat and particles from the burning plasma, the divertor is critical to a tokamak’s performance. But the new findings suggest that particles escaping the core plasma inside a tokamak collide with a larger area of the tokamak than once thought, greatly reducing the risk of damage.